Summary
Clonidine Hydrochloride has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Opioid Use Disorder would be drug repurposing rather than first-in-human development. This does not mean it is approved for Opioid Use Disorder. ClinicalTrials.gov lists 7 registered trials linking Clonidine Hydrochloride to Opioid Use Disorder: 1 is currently recruiting; 3 have completed; 3 are terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 4 (NCT03090152). The largest enrolment is 254 participants (NCT04600414). Registration activity spans 2013 to 2025. The literature layer holds 5 publications for this pair: 5 clinical trial publications. Publication years run from 1981 to 2005. These are primary trial reports rather than syntheses, so results have not yet been pooled or graded independently.
The RepurpOS disease-intelligence file for Opioid Use Disorder ranks 289 candidate therapeutics from Open Targets, ChEMBL, DGIdb and PubMed; only a minority carry direct clinical evidence, and this page covers one of those. Spontaneous remission context recorded for the condition: Spontaneous recovery (without MOUD) in 20-30% of OUD patients over 10 years; but overdose mortality risk during active disorder is extreme (5-10 per 1000 person-years); relapse rate 90%+ in first year after discontinuing MOUD.
Evidence table
| Evidence tier | A · Strong |
|---|---|
| Evidence score | 51.0 (trials 21.0, literature 10.0, tier 15, approved bonus 5.0) |
| Registered trials | 7 total: 1 recruiting, 0 active / not yet recruiting, 3 completed, 3 other |
| Linked publications | 5 (5 clinical trial publications) |
| Agent type | Drug (Small molecule) |
| Development stage (any indication) | Approved |
| Mechanism / class | agonist; agonist |
| Data sources | DGIdb |
| Linked via biomarker / target | ADRA2C |
How the evidence score is calculated
- Each registered trial scores by status (recruiting / active / enrolling 3, completed 2.5, not yet recruiting 2, unknown 1, terminated / withdrawn / suspended 0.5) plus a phase bonus (phase 3-4 +2, phase 2 +1, phase 1 +0.5). The trial component is capped at 30.
- Each literature item scores by design (Cochrane review 5, meta-analysis 4, systematic review 3, RCT 3, clinical trial publication 2, curated reference 1.5, other PubMed record 1). The literature component is capped at 30.
- The existing evidence tier adds 15 (A / Strong), 10 (B / Moderate), 5 (C / Preliminary) or 0 (D / Anecdotal).
- Agents approved for any indication (max clinical phase 4) add 5, because an approved agent has an established safety profile that lowers the barrier to repurposing trials.
- The score ranks what has been studied, not what works. It does not read effect sizes or directions of effect.
Registered clinical trials
| NCT ID | Title | Status | Phase | Enrolment |
|---|---|---|---|---|
| NCT03174067 | Buprenorphine in the Emergency Department 2013 | completed | Phase 4 | 26 |
| NCT03090152 | Minimal Opioid Use After Total Hip Replacement (THR) 2017 | completed | Phase 4 | 180 |
| NCT05172739 | Opioid Free Anaesthesia-Analgesia Strategy on Surgical Stress and Immunomodulation in Elective VATS-Lobectomy for NSCLC 2021 | recruiting | Phase 4 | 70 |
| NCT06137924 | Intraoperative Autonomic Neural Blockade 2023 | status unknown | Phase 3 | 150 |
| NCT03388814 | Speeding Recovery From Pain and Opioid Use 2018 | withdrawn | Early Phase 1 | — |
| NCT04600414 | Collaborating to Heal Addiction and Mental Health in Primary Care 2020 | completed | Not applicable | 254 |
| NCT06447194 | Effect of RECK in Posterior Spinal Fusion 2025 | withdrawn | PHASE1, PHASE2 | — |
Published literature
- Clinical trial publication Comparison of pharmacological treatments for opioid-dependent adolescents: a randomized controlled trialMarsch LA, Bickel WK, Badger GJ et al. · Archives of general psychiatry · 2005 · PMID 16203961
- Clinical trial publication Clonidine in morphine withdrawal. Differential effects on signs and symptomsJasinski DR, Johnson RE, Kocher TR · Archives of general psychiatry · 1985 · PMID 2413818
- Clinical trial publication Clonidine in outpatient detoxification from methadone maintenanceKleber HD, Riordan CE, Rounsaville B et al. · Archives of general psychiatry · 1985 · PMID 3977557
- Clinical trial publication Clonidine and naltrexone. A safe, effective, and rapid treatment of abrupt withdrawal from methadone therapyCharney DS, Riordan CE, Kleber HD et al. · Archives of general psychiatry · 1982 · PMID 7138234
- Clinical trial publication Clonidine in opiate withdrawal: review and appraisal of clinical findingsWashton AM, Resnick RB · Pharmacotherapy · 1981 · PMID 6765486
Mechanism and notes
Recorded mechanism or class: agonist; agonist.
OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in DGIdb, in this case via the biomarker or target ADRA2C. The tier describes how well the drug-disease link is documented, not how well the drug works.
Frequently asked questions
Is Clonidine Hydrochloride approved for Opioid Use Disorder?
Clonidine Hydrochloride has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Opioid Use Disorder would be drug repurposing rather than first-in-human development. This does not mean it is approved for Opioid Use Disorder. Approval status for the specific indication should always be confirmed with the relevant regulator and prescribing information.
Is Clonidine Hydrochloride in clinical trials for Opioid Use Disorder?
ClinicalTrials.gov lists 7 registered trials linking Clonidine Hydrochloride to Opioid Use Disorder: 1 is currently recruiting; 3 have completed; 3 are terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 4 (NCT03090152). The largest enrolment is 254 participants (NCT04600414). Registration activity spans 2013 to 2025.
What does the evidence show for Clonidine Hydrochloride in Opioid Use Disorder?
Clonidine Hydrochloride has 3 completed trials and 5 linked publications for Opioid Use Disorder. Completed trials may or may not have posted results; follow the NCT links to check. OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in DGIdb, in this case via the biomarker or target ADRA2C. The tier describes how well the drug-disease link is documented, not how well the drug works.
Cite this page
Data: ClinicalTrials.gov, PubMed, Open Targets, ChEMBL, DGIdb and the OSMF therapeutic agent database. Last updated 2026-07-05. Page built 2026-10-07.